SYSTEM = Al2O3
# Startparameter for this Run:
# NWRITE = 2 ! how much will be written to the file OUTCAR ('verbosity flag')verbosity write-flag
ISTART = 0 ! 0-new 1-cont 2-samecut job,/if WAVECAR exists 1 restart with constant energy cut-off'/2 restart with constant basis set': Continuation job -- read wave functions from the file WAVECAR
# ISPIN = 2 ! 1-no, 2-yes
INIWAV = 1 ! 0-jellium WF; 1-random numbers (recomm.)
ICHARG = 2 ! ISTART = 0 2, else 0
# WEIMIN = 0.001 ! for dynamic calculation IBRION >=0/for static calculation IBRION =-1
dynamic:
LPLANE = .TRUE.
NPAR = 8
# Electronic Relaxation
ENCUT = 350 ! Ecut (eV)
PREC = High ! precission: #Low for MD/Medium for optimization/Accurate for TS and frequence
EDIFF = 1.E-05 ! stopping-criterion for electronic upd.
LREAL = Auto ! .FALSE. projection done in reciprocal space/.TRUE. real space/On or O real space, projection operators re-optimized/Auto real space,fuly auto opti of projection operators no user interference required
NELMIN = 5 ! the minimum number of electronic SC steps
# NELM = 150 ! max. # of electronic SC steps
# NELMDL = 10 ! # of non-consistent steps at the beggining:>0 or <0
# LDIAG = .TURE. ! LDIAG = .TRUE. or .FALSE. (perform sub space rotation)
ALGO = Fast
# IALGO = 48 ! algorithm: use only 8 (CG) or 48 (RMM-DIIS)
GGA = 91 ! xc-type: PB, PW (86), LM, 91 (Perdew-Wang 91)
VOSKOWN = 1 ! it is desirable to use this interpolation for single atom or whenever the PW91 functional is applied.
ISMEAR = 0 ! part. occup.:-5 Blochl,-4 tet,-3,-2,-1-fermi,0-Gauss,>0MP broadening in eV -4 tet -1-fermi 0-gauss
SIGMA = 0.2 !
# IWAVPR = 12 ! if IBRION=0 (MD) 2,12/if IBRION=1,2 (relaxation) 1,11/else (static calculation) 0
# Ionic relaxation
EDIFFG = -0.05 ! break condition for the ionic relaxation loop/Default :EDIFF*10/negative ,will stop if all forces are smaller than [EDIFFG]
IBRION = 2 ! ionic relax: -1:no move; 0-MD;1-Newton;2-CG;3-damped;4-?
NSW = 400 ! steps for ionic update (def:0)
ISIF = 2 ! calc.stress:0-no;1-tr;2-7 yes; 3-change vol.4-change shape
POTIM = 0.3
# TS flags
IMAGES = 8
# NFREE = 2
SPRING = -5
ENERGY1 = -589.41939
ENERGY2 = -590.393218
# Write flags
LWAVE = .False. ! write WAVECAR
LCHARG = .False. ! write CHGCAR and CHG
LVTOT = .False. ! write the local potential LOCPOT
LELF = .False. !create ELFCAR file
LORBIT = .F. !create PROOUT
# Others
# APACO = 10.0 !distance for P.C.
AMIX = 0.2
BMIX = 0.0001
AMIX_MAG = 0.8
BMIX_MAG = 0.0001
用VASP做NBE计算,主要有这几个参数:
image=N, 初态与末态之间的image个数,SPRING=弹性恢复系数,用默认值-5就可以了,单位是ev/A^2,IBRION=1或3。在当前工作目录下要建N+2个子目录00,01,...,N+1.每个目录包括一个POSCAR,初态,末态的POSCAR分别放在00,N+1目录下面。中间的N个POSCAR需要在初态和末态之间通过线性插值得到。
VASP手册有Elastic band method这个小节。
对neb,取IBRION2,计算完neb 之后,IBRION取1结构优化,然后计算频率验证
NEB计算时,应该也是在算通过线性插值得到的中间态IMAGE的结构优化 那算完之后还要做IBRION=1的结构优化
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